climate change Flashcards
(21 cards)
areas of high rainfall
-highest concentration occurs at low altitudes near equator as strong heating of sun creates lasrge uplift of moist air
-or low heat results in frequent thunderstorms and prolonged showers (0-10 degrees latitude)
-eg: cherrapunji (north east Asia) one of wettest regions on earth (10,000mm per year) driven by monsoons and himalayas enhanving uplift of moist air
areas of low rainfall
-subropical zones (20-30 degrees latitude) dominated by dry descendning air and high pressure systems cuasing arid deserts
-eg: antartica: dry, high pressure, and lack of evaporation limits cloud formation (approximately 166mm p/a)
global temp: insolation
-varies with altitudes
-equatorial regions (eg amazon) recieve intentse direct sunlight: consistant high temps
-subtropical deserts (eg sahara desert) extreme heat from clear skies and minimal land cover.
atmospheric circulation
residtributes heat through 3 key cells
- hadley cells: warm air from equator- 30 degrees latitude= trade winds and dry conditions
- ferrel cells: westerly winds in midlatitude (30-60degrees latitude)moderating climates
-polar cells: circulate cold air between 60degrees lat and poles insolating cold polar regions
albedo
the amount of solar radiation reflected by the earths surface
-different land cover types have distinct albedo values- amount of heat retained or reflected
low: 0.05-0.10 eg asphalt absorb heat- UHI
high: 0.8-0.9 eg ice sheets reflect sunlight- polar areas and reinforcing cold conditions= feedback loops
heat budget and GHG effect
-regulate golbal temps
-maintains balance between incoming solar energy and outfoing thermal radiation
-GHG’s trap heat and disrupt heat budget
hydrological cycle
-regulates global climate by moving heat and moisture
-evaporation and condensation
CC accelerates hydrological cycle with more extreme weather conditions
- evapotranspiration: plants release water vapor influencing humidity and local climate
carbon cycle
-movement of carbon compuinds between ocean, land, atmosphere, living organisms
-as carbon enters ocean it sinks, storing for millions of years
-plants exchange with atmosphere- photosynthesis
-mainly impacts energy balance
rate if cliamate change
-intesifying at an accelerated rate
-increased temp
-increased sea levels (thermal expansion)
natural cause of CC: solar radiations
sunspot cycles (every 11 years) cause minor short-term impacts
-susnpots are huge magnetic storms that lead to more radiant energy being released
-eg: solar flares influence amount of insolation reaching earth
natural cause of CC: volcanic eruptions
-negligible: insiginificant
-sulphur aerosols emitted can cause short-term minimal global cooling bt reflecting solar radiation
-eg: mount tambora sumaba in indonesia 1815 errupted and killed 71000 people, called the volcanic winter
anthropogenic cause of CC: urbanisation
-elevated energy demands in urban areas due to infrastructureal use
-hevy reliance on fossil fuels
-urban sprawl increase vehicle emissions with lionger travel distances
-reduced vegetaiton from land clearing: diminishing natural carbon sequestration
decline in urban green spaces intesifies UHI effect and increase global climate stress
anthropogenic cause of CC: agriculture (rice)
-originally gown in flooded paddles- creating anaerobic (oxygen poor) conditions
-promote activity of methanogenic archaea producing methane during decomposition of organic matter
-glocal rise demand increase- contribution to GHG increase
evidence for CC through geological time: ice cores
-sceientists can work out the climate of the earth was like over 800000 years ago
-contains atmospheric compositions: trapped air bubbles- provide direct samples of past, the air bubbles trap past concentrations of CO2 and CH4 showing correlations between temperature changes and gas levels.
-use a specialised drill that bores down into ice sheets to remove a cylindrical tube- ice core
-precipitation patterns: the thickness of annual ice layer can indicated past snowfall quantities
-eg) european project for ice coring in antarctica (EPICA) drilled a core to 3190 meters, an age of 800000 years BP- revealing 8 previous glacial cycles
evidence for CC in recent human history: atmosphere
-temperature, caron dioxide levels, precipitation levels, humidity levels and air pressure are measured usually with satellite footage or ground instrumental temperature measurements. Thermometers are used to record temperatures.
-measurements have shown that each of the last 3 decades has been successively warmer at the Earth’s surface than any preceding decade since 1850
-globally, 19 out of 20 hottest years ever have occurred since the year 2000, apart from 1998 which saw a particularly warm year due to a strong el nino event
-rapid co2 increase- atmospheric carbon dioxide levels risen dramatically (419.3 parts per million in 2023, 250x faster than previous)
-global temp rise: earths average surface temp has increased by about 1.1 degrees C late 19th century
relationships between LCC and climate change in terms of albedo
high albedo surfaces (more reflected)
-snow and ice: reflect up to 90% of incoming solar radiation. melting ice reduces albedo, accelerating warming
-deserts and bare soil: reflect significant sunlight but contribute little to atmospheric moisture balance
low albedo surfaces (more absorptive)
-forests and dense vegetation: absorb more solar radiation, warming local environments but enhancing carbon uptake
-urban areas: asphalt, concrete, and dark rooftops reduce reflectivity- urban heat island
impact of LCC on albedo
-deforestation: often increases albedo when replaced with grasslands or crops. however, this gain in reflectivity is frequently outweighed by the loss of carbon storage (of a forest)
-afforestation and reforestation: can reduce albedo by introducing darker vegetation by provide significant cooling benefits through enhanced carbon sequestration.
relationshops between LCC and CC in terms of carbon sequestration
the process by which ecosystms absorb and store atmospheric CO2.
-a crucial role in climate regulation
-forests are major carbon sinks, absorbing CO2, through photosyntheisis and storing it in biomass and soil. tropical rainforests and boreal forests are especially effective on this role
-grasslands store substantial carbon underground within their extensive root systems
-wetlands and peatlands act as powerful carbon reservoirs. however, draining these ecosystems can release significant quantities of CO2 and methane
-oceans and coastal ecosystmes, such as mangroves and seagrass meadows, also play critical roles
-deforestation: releases stored carbon, accelerating atmospheric CO2 buildup
-agricultural expansion: distrubs soil carbon stocks, reducing the landscapes ability to sequester carbon
-reforestation and suitable land management practices enhanced carbon storage, mitigating climate change impacts
present impacts of CC on a natural environment: ice sheets and glaciers
-mass loss: both the Greenland and Antarctic ice sheets have been losing mass since 2002 – accelerated in recent years, rate of ice loss in antarctica multiplying x6 over thirty years by 2020
-sea level rise: melting ice sheets and glaciers accounting for 1/3 of observed local sea level rise
-glacier retreat: mountain glaciers worldwide are shrinking or disappearing- the world glacier monitoring service has reported ice loss for 36 consecutive years as of 2023
projected impacts of CC on a natural enviornment: ice sheets adn glaciers
-accelerated melting: ice loss is expected to continue accelerating eg) west antarctica-potential ice sheet collapse: realistiacally under high emission scenarios, significant portions of ice sheets could melt
-glacier disappearance: many mountain glaciers are projected to disappear entirely eg) new zealand, most glacier ice could be gone by 2100 (severe scenario)
present impacts of CC on an anthropogencic environment:
-increased heat stress: urban areas experiencing frequent and intense heat waves- exacerbated by the urban hear island effect
-flooding: many coastal cities- experience increased flooding, sea level rise, more intense precipitation events
-infrastructure stress: extreme weather events -cause pressure on urban infrastructure- water supply/availability and energy supply
projected impacts of CC on an anthropogenic environment
-sea level threat: coastal cities increasing sea level rise- significantly impact low-lying urban areas- forcing relocations
-water scarcity: urban areas, in arid regions, increased water stress- changing precipitation patterns and increased evaporation
-health risks: rising temps- changing disease vector ranges- increase health risks in urban populations eg) vulnerable populations
